With the aid of a satellite-based navigation system, the position of a vehicle can be determined with respect to a geocentric, three-dimensional coordinate system, such as, for example, length, width and height. In the case of such a system, which is also referred to as GNSS (Global Navigation Satellite System), a GNSS receiver in the vehicle receives GNSS signals from multiple satellites. In principle, the GNSS receiver determines—on the basis of orbital data and transmission time stamps contained in the signals—the transit time of the signals and, therefore, the distance to each satellite that was received. With the aid of the known satellite-based navigation systems, such as, for example, GPS (Global Positioning System) or GLONASS (GLObal NAvigation Satellite System), a horizontal position determination having an accuracy of approximately 10 meters can be achieved in the civilian sector. Nowadays, the accuracy can be increased to up to 2 centimeters (cm) by way of receiving and processing additional correction data. Such correction data are provided by different services. A transmission of the correction values takes place, for example, via cellular telephone or satellites.
Highly accurate satellite-based navigation systems are used, for example, for test purposes in test vehicles. In this case, changes in a system set-up or a configuration can quickly result in inaccuracies in a position determination. In addition, in modular navigation systems for installation into and removal from different test vehicles, a determination of the accuracy or errors in the position determination is necessary with each use, due to the highly precise absolute position determination. Thus there is a need for a rapid and highly precise measurement of the accuracy of a navigation system used for a traveling vehicle, which is carried out as simply as possible.
Known methods and systems are poorly suited for such a measurement. U.S. Pat. No. 7,797,132 B2, for example, describes a method and a system for testing the accuracy of a GPS navigation system for mobile communication devices, in which received GPS signals are initially evaluated and recorded during travel along a test route. The recorded GPS data are used by a GPS simulator in a laboratory for generating corresponding GPS signals. A stationary communication device located in the laboratory receives the simulated GPS signals and determines, therefrom, corresponding positions. The determined positions can be compared with the real route or with the position data determined by other communication devices in order to determine the performance of the navigation system.
One problem addressed by the present disclosure is that of providing a method and a system for determining the accuracy of a satellite-based navigation system, wherein the aforementioned disadvantages are avoided or are at least reduced and, in particular, a rapid execution of an accuracy determination with high precision and with as little effort as possible is made possible during an operation of a vehicle on a test route.
This problem is solved by a method and by a system for determining the accuracy of a satellite-based navigation system for a vehicle during operation on a test route.